Generally, continuous form computer printers or copiers are fed fanfold or zigzag-folded paper having a rather long length (continuous form) from a stack. Each panel or sheet of the continuous form is usually defined by transverse perforations or scoring. In the formation of a stack of fanfold continuous form paper, the paper is folded back and forth and creased at the perforations defining alternate fold lines until the desired stack height is obtained. As the paper is being oppositely folded at the perforations or scoring, the paper fibers are given an initial directional fold memory, to facilitate refolding and restacking of the fanfold paper at the original fold lines. Examples of fanfold paper folding devices are illustrated in the following United States patents:
______________________________________ U.S. Pat. No. Inventor(s) Issue Date ______________________________________ 1,985,676 Hand Dec. 24, 1934 2,495,994 Ward et al. Jan. 31, 1950 3,124,350 Huffman Mar. 10, 1964 3,547,430 Assony Dec. 15, 1970 3,912,252 Stephens Oct. 14, 1975 4,151,985 Gladow May 1, 1979 4,332,581 Thompson Jun. 1, 1982 4,508,527 Uno et al. Apr. 2, 1985 4,820,250 Bunch, Jr. Apr. 11, 1989 4,917,657 Bunch, Jr. Apr. 17, 1990 4,976,677 Siversson Dec. 11, 1990 5,123,890 Green, Jr. Jun. 23, 1992 5,149,075 Crowley et al. Sep. 22, 1992 ______________________________________
However the strength of the directional fold memory of the paper at each fold line is frequently weakened as the paper passes through the printer, making it difficult for the printer outfeed collector to reform the paper into a neat and orderly stack. The problem is particularly magnified when the fanfold paper is fed through an electrophotographic printer having high temperature fuser rollers that "iron out" the fold lines.
Several solutions have been proposed for engaging or reflecting the ironed out perforation edges as the paper leaves the printer to facilitate the orderly refolding and restacking of the continuous form paper. Two such proposed solutions to this problem have been suggested in the Negoro et al. U.S. Pat. No. 5,082,382, issued Jan. 21, 1992 and the Bergeman et al. U.S. Pat. No. 5,123,894 issued Jun. 23, 1992, along with other patents classified in U.S. Class 400, subclass 613.2
Analog Technology Corporation of Duarte, Calif., USA, is presently selling opposed moving belt devices under the brand name "Paper Cat", that are mountable along the sides of a printer outfeed collector with belt-teeth to engage and move the fold lines downward to assist in refolding fanfold paper discharged from the printer.
Applicant has invented a very clever and inexpensive "Printer Outfeed Paper Collector" that is quite effective in refolding and restacking fanfold paper discharged from a continuous form printer that is described in U.S. patent application Ser. No. 08/197,080 filed 16 February 1994, and issued as U.S. Pat. No. 5,358,345, issued Oct. 25, 1994.
However, despite the effectiveness of the Applicant's "Printer Outfeed Paper Collector", Applicant has found that, particularly for rather large stacks, the effectiveness may be diminished due to the excessive height build up at the perforated edges of the stack in relation to the center of the stack. Such differential build-up causes the upper layer of the stack to be seriously concave in shape, making refolding more difficult.
The problem is illustrated in FIGS. 1 and 2 in which a printer output paper collector, generally designated with the numeral 10 is designed to operate in conjunction with a continuous form printer 12 that has a paper input section 14 and a paper output section 16. The collector 10 refolds and restacks fanfold or zigzag paper 20 that is discharged from the output section 16 of the printer 12. The fanfold paper 20 is initially stored in a stack 22 adjacent the input section 14. The stack 22 is frequently contained in a stack container or bin 24. The fanfold paper 20 has sheets or panels 26 between fold or crease lines 28.
The continuous form printer 12 at the input section 14 includes an optional input guide 30 for guiding the paper from the stack 22 into the printer 12. An output guide 32 is mounted at the output section 16 for directing paper discharge from the printer in a downward orientation as illustrated.
The collector 10 includes a frame 40 having a base 41 that is generally floor mounted. The frame 40 includes a printer stand section 42 that extends upward from the base 41 to support the printer 12. The base 41 includes a restacking section 44 with a restack platform 46. The platform 46 has a paper break element 48.
The restacking section 44 further includes opposing end walls 50 and 52 that are positioned for receiving a restack 56 of the fanfold paper 20. Although not illustrated, the end walls 50 and 52 may be adjusted with respect to each other to accommodate different length sheets 26. The restacking section 44 also includes a back wall 54 and a front opening to permit a restack of the fanfold paper to be removed as necessary.
FIG. 1 illustrates the printer paper output collector 10 during the initial formation stage of restacking the fanfold paper. It should be noted that a lower or bottom layer 60 of the restack is bowed in an upward concave arc with sheet ends of the lower layer drooping downward engaging the platform 46. A top layer 62 of the restack 56 is beginning to be bowed with a downward concave arc in which the sheet ends 58 of the top layer 62 are vertically above the center of the top layer 62.
FIG. 2 illustrates the printer paper output collector 10 after the restack has obtain a substantial height. The lower layer 60 has maintained its initial contour while the top layer 62 of the restack has progressively increased its downward concave arc with a smaller radius of curvature. As illustrated, the sheet ends of the top layer 62 have increased their heights relative to the center of the top layer 62.
One technique to minimize the formation of the excessive concave bowing of the upper layers of a rather tall stack is to provide paper breaks at the bottom of the stack to cause the lower layers to conform to an upward concave configuration. Examples of such paper break devices are illustrated in the Moore et al. U.S. Pat. No. 5,238,316 granted Aug. 24, 1993, the McIntosh Sr. et al. U.S. Pat. No. 4,226,410 granted Oct. 7, 1980 and the Clark U.S. Pat. No. 4,707,157 granted Nov. 17, 1987. The Kelley U.S. Pat. No. 4,941,654 shows a paper break used in the stacking on successive single sheets.
Although such prior art devices may assist in refolding and restacking fanfold paper, they are either too expensive or are only moderately successful. For example, the paper break illustrated in the Moore et al. U.S. Pat. No. 5,238,316 is rather expensive and does not automatically adjust to various height stacks.
One of the advantages of the present invention is to provide a resilient paper support assembly that it is rather inexpensive and quite reliable and effective in both refolding and restacking fanfold paper discharged from the output of a computer printer independently of the height of the stack to maintain the top layer of the stack rather flat as subsequent sheets are being added.
These and other objects and advantages of the present invention will become apparent in reviewing the following detailed description of a preferred embodiment.